The Genome Sciences group provides researchers with multiple complementary tools for genome interrogation including: rapid scanning of genomes for new mutations causing relevant phenotypes;mapbuilding using microsatellite and/or SNP markers, including data analysis and new marker development; high throughput microsatellite allele typing and SNP genotyping;DNA sequencing;and highly purified DNA from JAX mouse strains that is used routinely in experiments as controls. Genome Sciences (GS) comprises the following services: 1) Allele Typing &Sequencing;2) Single Nucleotide Polymorphism genotyping;3) Fine Mapping;and 4) the DNA Resource. GS provides researchers with access to stateof- the-art instrumentation, reagents and expertise for genome scanning, allele typing, and sequencing, including support in project planning and data analysis. Sequencing and Allele typing have previously received CCSG support. CCSG funds are now requested for the SNP Genotyping Service and the Fine Mapping Laboratory, which have been in operation for 2 and 3 years, respectively, with well established records of delivering additional functionality as required by Cancer Center members. Operating since 1982, the DNA Resource maintains and distributes highly purified genomic DNA, which is used by virtually all Center researchers for controls in genome analysis experiments including the cloning of spontaneous mutations. Genome Sciences, which occupies 847 ft2 of laboratory space in Research Laboratory Unit 4 and the Genetic Resources Building, employs four molecular technologists, and four laboratory technicians all reporting to a senior manager molecular geneticist. Project Leader Jurgen Naggert, a molecular geneticist, oversees this fee-for-service operation. He communicates with the Cancer Center users, Service staff and Center Administration to ensure that research needs are met in the most efficient, cost-effective and technically current manner.